One of my questions is does this piece that retains the onstar and door chimes, does it work with the bose system or do i need something in addition to that one? I know when you replace a radio with an aftermarket one you need to buy a wiring harness and im wondering if this is the wiring harness.

If there is anyone who did their own installation can you please tell me what parts you used and what you did?

I looked into doing an aftermarket radio a while back. Basically you need to buy the harness you found as well as another one which will give you access to your steering wheel controls. I decided after all was said and done to keep the factory radio and just add a good speakers and an amp.

I am doing the same thing here real soon. I have decided to use the pac os3(os3bose for bose applications, i don't have it) connected to a pac swi jack for steering wheel contorls for the alpine im getting. Then, to keep the onstar through the front speakers a speaker line inverter thing to make the front speakers wires rca's. Alpine pdx amps under the center console and Alpine spx refs in the doors.